International law is the law that governs human activities and relationships at the international level. The major actors in the international arena are states and international organisations. So traditionally international law is primarily concerned with the conduct of states and international organisations. But in the recent decades individuals, transnational corporations and non-governmental organisations are becoming increasingly active in international affairs, and their activities are also relevant to international law.
The major topics covered in an international law course include: treaties (agreements between states dealing with any matters of international concern); jurisdiction (power of a state to make and enforce its laws at the international level); state responsibility for wrongful acts; the use of international law in domestic courts; human rights; war and peace; international organisations, etc. The basic purpose of studying international law is to understand the concepts, principles and methods of international law as distinct from domestic law and thereby understand the special environment, structure and process of international transactions.
International vs. National Law
The relationship between international law and national law (municipal law or domestic law as it is also called) is one of the most intriguing, variable, and I dare say complex, issues that arises in the context of the application of international law.
First, international legal obligations can be thought of as existing on two simulataneous planes: the international plane and the domestic plane. They are not necessarily the same and in many cases are quite different. Obligations that exist on the international plane are those between states themselves. States, of course, being the central actors in international law. These obligations arise as a result of treaties and customs that evolve over time.
These obligations, however, may produce different consequences when they are considered on the domestic plane. Here countries differ greatly with regard to the hierarchy or normative rank that their individual legal systems assign to international obligations. Typically, states will draw distinctions between obligations arising under treaty and those arising through customary law. Rarely, states consider international obligations superior to their domestic laws but in many more cases international obligations are considered on a par with, and part of, a state’s body of domestic law. In other cases, international obligations are made a part of a state’s domestic law by specific implementing legislation that converts an international obligation into a corresponding domestic one. Where this fails to occur, the state will be bound by the obligation on the international plane, but no rights flow from that obligation to the domestic plane.
In the United States, treaties are considered to have the dignity of an act of Congress, that is federal statutory law, while customary law has the rank of federal common law (judge-made law). Note they are both considered inferior to obligations of a Constitutional magnitude.
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